In order to monitor the movement of rail vehicles on railway tracks, rail vehicles can be detected at fixed positions along the railway track. The fixed position sensors can, for example, provide the information if a rail vehicle passes their fixed position. By employing two or more position sensors, moving rail vehicles can be detected at several positions. With this, it can be determined if a rail vehicle is located in a certain track area between two position sensors. By evaluating the output signals of the two position sensors, certain track areas can be determined to be clear of a rail vehicle or occupied by a rail vehicle.
By employing at least two position sensors in close proximity, the velocity and the direction of travel of a moving rail vehicle can be determined. By counting the number of axles of a rail vehicle passing over a position sensor the length of a rail vehicle can be determined. Moreover, it is possible to determine on which track a rail vehicle is moving by positioning position sensors on each track.
However, with these fixed position sensors it is not possible to obtain any information about the movement of a rail vehicle between two position sensors. Thus, it is only possible to obtain information about the rail vehicle such as the velocity or the direction of travel at the fixed positions of the position sensors.